> folks.i wonder if a 2001 ECU will work in a 2000 car. "half chip"
> and probably a
> little more stable to drive.
Nope. 2001 1.8t has VVT (variable valve timing) and 2000 doesn't. In fact the '01 engine was overhauled quite extensively to attain ULEV standard (first turbo engine in the world to attain such emission standard). In addition to VVT, it also got different software (runs more boost, 9 psi vs 7 psi) and different internals (cast pistons vs. forged ones in earlier engines, not sure about crank and connecting rods).
2000 1.8t gets ~205hp when chipped, and I believe 2001 gets a few extra ponies generally.
Quincy